Originally Posted by straightaway

Hi all,

Can someone tell me how to tune engine at night when it is 20-25 degree cooler? Someone at the track say to rich it up and also run colder plugs? Is that ture? It does not seem right. I always thought you lean it out a bit becasue the outside temp is cooler. Also run a hotter plug to keep the engine a bit warmer.

Also what happens when the enviroment is damp/foggy? do you lean out or rich up the engine?